FDA approves new drug for potentially deadly ammonia conditions

SILVER SPRING, Md. — The Food and Drug Administration has approved a new drug for treating some disorders that harm the body's ability to remove ammonia from the blood, the agency said Friday.

The FDA announced the approval of Hyperion Therapeutics' Ravicti (glycerol phenylbutyrate) for the chronic management of certain urea cycle disorders in patients ages 2 years and older. Normally, when protein is absorbed and broken down by the body, it produces nitrogen as a waste product, which the urea cycle removes through the urine. But in people with UCDs, the nitrogen accumulates in the body as ammonia, which can travel to the brain and cause brain damage, coma or death.

"Ravicti provides another treatment for chronic management of urea cycle disorders, a group of life-threatening conditions," FDA Division of Gastrointestinal and Inborn Errors Products director Donna Griebel said. "The approval of this new therapeutic option demonstrates FDA's commitment to providing treatments for patients suffering from rare diseases."

The drug is a liquid taken three times a day with meals and is intended for patients whose UCD can't be managed with a protein-restricted diet or amino acid supplements alone.